JP2020111728A - Azo pigment composition and method for producing the same - Google Patents

Abstract

To provide an azo pigment composition that can improve the brightness and contrast of a color filter, and the printing concentration (color development) of printed matter by inkjet, and a method for producing the same.SOLUTION: The present invention provides a method for adding, when producing an azo pigment that is a reaction product between a base represented by formula (1) and a coupler represented by formula (2), a dissimilar base and a dissimilar coupler (in formula (1), R1 is R3-NH-C(=O)-, R2 is a halogen atom or the like, R3 is a hydrogen atom or the like; in formula (2), R5 is a hydrogen atom or the like).SELECTED DRAWING: None

Description

The present invention relates to an azo pigment composition and a method for producing the same.

Azo pigments are widely used as colorants such as paints, offset inks, gravure inks, color toners, inkjet inks for recording, and colorants for color filters. In order to improve various characteristics such as brightness and contrast of the coating film formed in these applications, a finely divided azo pigment may be used. However, it is generally known that a coloring composition containing a finely divided pigment tends to have poor dispersion stability. Therefore, measures have been proposed for ensuring dispersion stability of pigments and the like and improving various properties thereof (Patent Documents 1 to 6).

Patent Document 1 contains an organic pigment, a pigment dispersion aid A which is a sulfonated compound having the same skeleton as the organic pigment, a pigment dispersion aid B having a specific structure, a pigment dispersant, and an organic solvent. In the production of a red pigment dispersion for a color filter, a step of mixing a dispersion aid A and an organic pigment to carry out a micronization treatment, and then mixing a pigment dispersion aid B, a pigment dispersant and an organic solvent to carry out a dispersion treatment. It is described to do. It is said that by using two kinds of pigment dispersion aids in this way, fine dispersibility of the pigment and subsequent dispersion stability are improved, and excellent color characteristics, high transmittance, and contrast can be realized.

Patent Document 2 is characterized by containing a colorant (A) containing a red azo pigment (a1) having a maximum refractive index of 1.8 or less in a light wavelength region of 600 to 700 nm, and a resin (B). And a coloring composition for a color filter. When such a pigment (a1) is contained, it is said that the pigment is excellent in stability because it does not need to be excessively miniaturized while having a high contrast ratio.

Patent Document 3 describes C.I. I. Pigment Red 221 is made into fine particles, and a finely divided product is obtained by adding a pigment dispersion aid having a specific structure, an acrylic block copolymer having a tertiary amino group and/or a quaternary ammonium group, and an organic solvent. In addition, a method of preparing a red pigment-dispersed resist composition for a color filter after dispersing to obtain a pigment dispersion is described. By this method, C.I. I. The dispersion stability of the fine particles of the pigment including Pigment Red 221 can be remarkably improved as compared with the prior art, and the dispersion stability, coloring power, contrast, brightness, heat resistance, and solvent resistance are excellent. It is said that a red pigment-dispersed resist composition for a color filter can be provided.

Patent Document 4 describes that naphthol red having a specific structure can be obtained by surface-treating the naphthol red having a specific structure with a hydrophilic naphthol derivative or a hydrophilic phenol derivative having a specific structure to obtain naphthol red excellent in dispersibility, color development, and transparency. Has been done.

In Patent Document 5, in the production of a monoazo red pigment composition containing a monoazo pigment having a specific structure and an azonaphthoic acid component having a specific structure, a monoazo pigment having a specific structure is produced by a coupling reaction between a diazonium salt component and a coupler component. It is described that the synthesized azonaphthoic acid component can be obtained by adding hydroxynaphthoic acid to the coupler component in advance before the coupling reaction. The monoazo red pigment composition thus obtained and the color toner using this composition maintain the reflection characteristics in the yellow region of the monoazo red pigment and have good reflection properties in the bluish region. It is described that it has a wide reproduction range, has sufficient brightness and saturation, and is excellent in transparency, light resistance, and dispersibility.

US Pat. No. 6,096,697 describes inkjet inks containing specific polymer-bonded pigments dispersed in an aqueous ink vehicle. It is said that with such a configuration, it is possible to provide an inkjet ink that can generate a printed image having good glossiness and durability without increasing the ink viscosity.

JP, 2011-162722, A JP2012-198453A JP, 2016-61979, A JP, 2016-108451, A JP 2000-248191 A Japanese Patent No. 4532387

For example, in the field of display devices in which color filters are used and in the field of inkjet inks for recording, there is a strong demand in the market for higher image quality, and even if the inventions described in Patent Documents 1 to 6 are adopted, it is still improved. There is room for Therefore, an object of the present invention is to provide an azo pigment composition capable of improving brightness and contrast as compared with conventional ones in the field of display devices in which color filters are used, and a method for producing the same. is there. Further, in the field of inkjet inks for recording, it is an object of the present invention to provide an azo pigment composition capable of improving a printing density (coloring property) as compared with a conventional one, and a method for producing the same.

In order to solve the above-mentioned subject, the present inventor has conducted earnest studies. As a result, when a specific azo pigment is produced and a coupling reaction is performed by adding a base and a coupler different from the base and the coupler, for example, in the field of a display device in which a color filter is used, it is obtained. Brightness and contrast of a coating film containing the pigment composition obtained, and, for example, in the field of inkjet ink for recording, a print density (coloring property) of a printed matter containing the obtained pigment composition is improved as compared with the conventional one. The inventors have found that it is possible and have completed the present invention.

The first aspect of the present invention is that when a azo pigment, which is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2), is produced, a heterogeneous compound represented by the formula (3) The present invention relates to a method for producing an azo pigment composition, in which a base and a heterogeneous coupler represented by the formula (4) are added.

(In the formula (1), R ¹ represents R ³ —NH—C(═O)—, R ² represents a halogen atom or R ⁴ O—, and R ³ represents a hydrogen atom or a phenyl group (—C ₆ H). ₅ ), and R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ —NH—C(═O)—, R ⁸ represents a halogen atom or R ¹⁰ O—, and R ⁹ represents a hydrogen atom or a phenyl group (—C). ₆ H ₅ ), R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

(In the formula ^{(4), R 11} represents an -SO ₃ H or -COOH.)

In the embodiment of the present invention, 0.5 to 4 parts by weight of the base represented by the formula (3) and 100 parts by weight of the coupler represented by the formula (2) are used with respect to 100 parts by weight of the base represented by the formula (1). On the other hand, 2 to 10 parts by weight of the coupler represented by the formula (4) may be added.

In the embodiment of the present invention, the azo pigment may be subjected to a refining treatment so that the average primary particle diameter of the azo pigment becomes 25 to 70 nm. Further, in this case, the fine treatment may be performed in the presence of the pigment derivative.

A second aspect of the present invention is an azo pigment composition containing an azo pigment which is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2): The reaction product of the base represented by (3) and the coupler represented by formulas (2) and (4) is contained, and the content of the reaction products of formulas (1) and (2) (based on solid content) is 80. ~95 wt% azo pigment composition.

(In the formula (1), R ¹ represents R ³ —NH—C(═O)—, R ² represents a halogen atom or R ⁴ O—, and R ³ represents a hydrogen atom or a phenyl group (—C ₆ H). ₅ ), and R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ —NH—C(═O)—, R ⁸ represents a halogen atom or R ¹⁰ O—, and R ⁹ represents a hydrogen atom or a phenyl group (—C). ₆ H ₅ ), R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

(In the formula ^{(4), R 11} represents an -SO ₃ H or -COOH.)

In the present invention, the weight ratio ((1)/(3)) of the component derived from the formula (1) and the component derived from the formula (3) is 90.6/9.4 to 98.9/1.1. And the weight ratio ((2)/(4)) of the component derived from the formula (2) and the component derived from the formula (4) is 82.4/17.6 to 96.5/3.5. Good.

According to the present invention, for example, in the field of a display device in which a color filter is used, the brightness and contrast of a coating film containing the obtained pigment composition, and, for example, in the field of inkjet ink for recording, an inkjet method is used. It is possible to provide an azo pigment composition capable of improving the print density (coloring property) of the printed matter of the present invention more than ever before and a method for producing the same.

Hereinafter, embodiments of the present invention will be described.

In the embodiment of the method for producing an azo pigment composition according to the present invention, in producing an azo pigment which is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2), A heterogeneous base represented by formula (3) and a heterogeneous coupler represented by formula (4) are added. In addition, below, the base shown by Formula (1) may be called a main base, and the coupler shown by Formula (2) may be called a main coupler. Further, an azo pigment obtained from the main base and the main coupler may be referred to as a main azo pigment.

(In the formula (1), R ¹ represents R ³ —NH—C(═O)—, R ² represents a halogen atom or R ⁴ O—, and R ³ represents a hydrogen atom or a phenyl group (—C ₆ H). ₅ ), and R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ —NH—C(═O)—, R ⁸ represents a halogen atom or R ¹⁰ O—, and R ⁹ represents a hydrogen atom or a phenyl group (—C). ₆ H ₅ ), R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

(In the formula ^{(4), R 11} represents an -SO ₃ H or -COOH.)

In this way, by adding a base and coupler that are different from the main base and main coupler that make up the specific azo pigment, the brightness and contrast of the color filter or the print density (coloring property) of inkjet prints can be improved. The reason why it is possible is to use the presence of reaction products (hereinafter sometimes referred to as by-products) other than the main azo pigment produced due to the presence of different types of bases and couplers. It is assumed that this is due to the suppression of crystallization and crystal growth of the azo pigment). It is speculated that by suppressing the crystallization or crystal growth in this way, the aggregation of the main azo pigment is also suppressed, and it is possible to improve the brightness and contrast of the color filter or the print density (color developability) of the inkjet type printed matter. It

As the main base, the one represented by the above formula (1) can be used. In formula (1), the bonding positions of R ¹ and R ² are not particularly limited. R ¹ may be NH ₂ —C(═O)— or C ₆ H ₅ —NH—C(═O)—. R ² may be a halogen atom or R ⁴ O—. The halogen atom may be any of chlorine atom, bromine atom and the like. R ⁴ may be an alkyl group having 1 to 4 carbon atoms, and may be a methyl group, an ethyl group, a propyl group or a butyl group. The propyl group and the butyl group may be linear or branched. Examples of such a base include 3-amino-4-methoxybenzanilide, 2-chloro-5-methoxyaniline, 3-chloro-6-methoxyaniline and the like.

As the main coupler, the one represented by the above formula (2) can be used. In formula (2), R ⁵ may be a hydrogen atom or -CONH-R ⁶ . R ⁶ may be any functional group represented by the formula (2-1), and the bonding positions of R ⁷ and R ^{8 in} the formula (2-1) are not particularly limited. R ⁷ _{is, NH 2 -C (= O)} - or _{C 6 H 5 -NH-C (} = O) - may be any. R ⁸ may be a halogen atom or R ¹⁰ O—. The halogen atom may be any of chlorine atom, bromine atom and the like. R ¹⁰ may be an alkyl group having 1 to 4 carbon atoms, and may be a methyl group, an ethyl group, a propyl group or a butyl group. The propyl group and the butyl group may be linear or branched. Examples of such a coupler include N-(5-chloro-2-methoxyphenyl)-3-hydroxy-2-naphthalenecarboxamide and β-naphthol.

The heterogeneous base with respect to the main base described above may be the one represented by the equation (3). In formula (3), the bonding position of the sulfonic acid group is not particularly limited. Such heterogeneous bases include p-aminobenzoic acid (sulfanilic acid), o-aminobenzoic acid (anthranilic acid), m-aminobenzoic acid. One type of different base may be used, or two or more types may be used.

The heterogeneous coupler with respect to the main coupler described above may be the one represented by the formula (4). In formula (4), the bonding position of R ¹¹ is not particularly limited. R ¹¹ may be —SO ₃ H or —COOH, but —COOH is preferable. Examples of such heterogeneous couplers include β-naphthol, BON acid, Sheffer acid, F acid and the like.

The different types of bases and couplers may be present in the coupling reaction using the main base and the main coupler. For example, (1) a diazotized solution obtained by diazotizing a solution containing a main base and a heterogeneous base is mixed with a coupler solution containing a main coupler and a heterogeneous coupler to cause a coupling reaction, and (2) a diazotized solution of the main base. And a coupler solution containing a main coupler are mixed to perform a coupling reaction, a diazotized solution of a heterogeneous base and a coupler solution of a heterogeneous coupler are added separately from the main base and the main coupler, and a coupling reaction is performed, etc. The method of can be adopted. The diazotization of the base and the coupling reaction can be carried out by employing known conditions.

The mixing ratio of the main base and the heterogeneous base obtains the main azo pigment as the main colorant, secures the characteristics of the main azo pigment, and crystallizes the desired azo pigment with a product derived from the heterogeneous base and the coupler. From the viewpoint of effectively suppressing crystal growth, it is preferable to add the different base in an amount of 0.5 to 4 parts by weight with respect to 100 parts by weight of the main base.

For the same reason, the mixing ratio of the main coupler and the heterogeneous coupler is preferably 2 to 20 parts by weight of the heterogeneous base with respect to 100 parts by weight of the main base.

After the coupling reaction, a dried product of the azo pigment composition is obtained by filtering, washing with water and drying. It is also possible to use this dried product as it is as an azo pigment composition. It is also possible to use a pulverized product obtained by pulverizing a dried product as an azo pigment composition. It is also possible to use, as an azo pigment composition, a fine product obtained by subjecting a dried product or a pulverized product to a fine process.

The pulverized product can be obtained by pulverizing with a disperser such as a roll mill or a bead mill. Further, the finely divided material can be obtained by, for example, a salt milling method or the like. Micronization by a salt milling method, particularly a solvent salt milling method, for example, a dried or pulverized product of a pigment composition, a water-soluble inorganic salt and a water-soluble solvent are mixed, and the resulting mixture is mixed with a kneader or the like. It is carried out by mechanically kneading and grinding the pigment composition with a water-soluble inorganic salt. For such salt milling, conventionally known conditions can be adopted. After salt milling, the product is washed with water to remove the water-soluble inorganic salt and the water-soluble solvent to obtain a finely divided pigment composition. Washing with water is preferably performed until the water-soluble inorganic salt and the water-soluble solvent are completely removed. It may be dried to remove water depending on the use.

When performing the micronization treatment, the micronization treatment may be performed in the presence of a surface treatment agent such as a pigment derivative or a resin from the viewpoint of more effectively suppressing crystallization and crystal growth of the azo pigment. For example, in the case of the solvent salt milling method described above, a surface treatment agent may be present when the pigment composition is ground with a kneader. The surface treatment agent may be added in the entire amount at the start of kneading or may be added in a plurality of times after the start of kneading.

The pigment derivative is a compound in which an organic pigment has a basic skeleton and an acidic group or an aromatic group is introduced into a side chain as a substituent. Specific examples of the organic skeleton that serves as a base skeleton include quinacridone pigments, phthalocyanine pigments, azo pigments, quinophthalone pigments, isoindoline pigments, isoindolinone pigments, quinoline pigments, diketopyrrolopyrrole pigments, and benzo pigments. Examples thereof include imidazolone pigments and dioxazine pigments. The mother skeleton also includes naphthalene-based, anthraquinone-based, triazine-based, and quinoline-based light yellow aromatic polycyclic compounds, which are generally not called dyes. Examples of such a pigment derivative include, for example, JP-A-11-49974, JP-A-11-189732, JP-A-10-245501, JP-A-2006-265528, and JP-A-8-295810. JP-A-11-199796, JP-A-2005-234478, JP-A-2003-240938, JP-A-2001-356210, JP-A-2007-186681, JP-A-2003-167112, and JP-A-2003-167112. What was described in 2013-199470 publication etc. can be used.

The addition amount (nonvolatile content or solid content) of the pigment derivative is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the pigment composition.

Examples of the resin as the surface treatment agent include vinyl ester resin and acrylic resin. The addition amount of the resin as the surface treatment agent is preferably 3 to 30 parts by weight with respect to 100 parts by weight of the pigment composition.

The average primary particle diameter of the azo pigment in the finely divided pigment composition is preferably 25 to 70 nm. Such an average primary particle diameter is, for example, from an image of 50,000 times and 100,000 times by a transmission electron microscope (trade name: JEM-1011, manufactured by JEOL Ltd.), 50 arbitrary fine pigment particles Can be selected, the maximum particle size of each finely divided pigment particle can be measured based on the measuring scale shown in the image, and can be determined as an arithmetic mean.

In the case of an inkjet ink, the average particle diameter of the secondary particles of the pigment is preferably from the viewpoint of improving the dispersibility, and from the viewpoint of the dischargeability from the ink discharge nozzle provided in the inkjet recording type printing machine. It is 300 nm or less, more preferably 150 nm or less. The average particle size of the secondary particles of the pigment contained in the pigment composition used for the inkjet ink is a measurement value obtained when the particles contained in the inkjet ink coloring composition or the inkjet ink are measured with a laser zeta electrometer. Shall mean.

The pigment derivative may be added after the refinement treatment and mixed in addition to being present when the refinement treatment is performed.

An embodiment of the azo pigment composition according to the present invention includes an azo pigment which is a reaction product of the base represented by the above formula (1) and the coupler represented by the above formula (2). In addition, the reaction product of the formula (1) and the formula (2) containing the reaction product of the base represented by the formulas (1) and (3) and the coupler represented by the formulas (2) and (4). The product content (based on solids) is preferably 80 to 95% by weight. Such an azo pigment composition is obtained, for example, by the above-mentioned manufacturing method.

The azo pigment composition obtained by the above-mentioned production method involves a heterogeneous base and a coupler in addition to the main azo pigment which is a reaction product produced by the coupling reaction between the main base diazotized product and the main coupler. And by-products produced by the coupling reaction. As described above, it is considered that crystallization and crystal growth of the main azo pigment are suppressed by the by-products formed by the involvement of the heterogeneous base and the coupler. From the viewpoint of exerting the function of the main azo pigment itself and effectively operating the function of the by-product to improve the brightness and contrast of the color filter or the printing density (coloring property) of the ink jet type print, The preferable range of the content (based on solid content) is as described above. In other words, the content of the by-product (based on solid content) is preferably 20 to 5% by weight.

The azo pigment composition contains a pigment derivative when it is subjected to the refining treatment using the pigment derivative and when the pigment derivative is added after the refining treatment. In this case, the content (based on the solid content) of the main azo pigment is preferably 64 to 94% by weight.

Regarding the composition of the main azo pigment and the by-product contained in the azo pigment composition, the function of the by-product is exerted to further improve the brightness and contrast of the color filter or the print density (coloring property) of the inkjet type print. From the viewpoint, the weight ratio ((1)/(3)) of the component derived from the formula (1) and the component derived from the formula (3) is 90.6/9.4 to 98.9/1.1. The weight ratio ((2)/(4)) of the component derived from the formula (2) and the component derived from the formula (4) is 82.4/17.6 to 96.5/3.5. preferable.

The composition of the main azo pigment and the by-product can be understood from the composition ratio of the starting materials, but it can also be measured by gas chromatography mass spectrometry (GC/MS) using the obtained azo pigment composition. is there.

The main azo pigments contained in the embodiment of the manufacturing method and the azo pigment composition according to the present invention are exemplified by C.I. I. Pigment Red 269 and the like.

The azo pigment composition as described above can be used as a colorant such as a paint, an offset ink, a gravure ink, a color toner, a recording inkjet ink, and a colorant for a color filter. It is particularly suitable as a colorant for color filters of image display devices, because it can improve the brightness and contrast as compared with conventional ones. Further, in recent years, in an image display device using a color filter, various light sources such as a cold cathode tube, a light emitting diode, and an organic EL element have been adopted as a backlight of a light source. The light reproducibility is good and good brightness is obtained in various color gamuts even when the above light source is used. Further, since the printing density (color-forming property) can be improved more than ever before, it is also suitable as a colorant for recording ink-jet inks and the like.

In the following, first, an outline of a coating film-forming coloring composition for a color filter will be described, taking as an example the case where the above-described azo pigment composition is used as a coloring agent for a color filter.

The coating film-forming coloring composition contains the above-mentioned azo pigment composition, a dispersant, a dispersion aid, a solvent, a coating film forming component, and other additives. Among these, a dispersion aid, a solvent, and other additives can be added as necessary according to the components of the azo pigment composition.

Examples of the dispersant include a resin type dispersant and a surfactant type dispersant. Specific examples of the resin-type pigment dispersant include, for example, polyurethane, polyester, unsaturated polyamide, phosphoric acid ester, polycarboxylic acid and its amine salt/ammonium salt/alkylamine salt, polycarboxylic acid ester, hydroxyl group-containing polycarboxylic acid ester, Oil-based dispersants such as polysiloxane and modified polyacrylate, water-soluble (meth)acrylic acid-(meth)acrylic acid ester copolymers, (meth)acrylic acid-styrene copolymers, styrene-maleic acid copolymers, etc. Examples thereof include resins and water-soluble polymer compounds. As the surfactant type pigment dispersant, a naphthalenesulfonic acid formalin condensate salt, an aromatic sulfonic acid formalin condensate, an anionic activator such as polyoxyethylene alkyl phosphate ester, a nonionic activator such as polyoxyethylene alkyl ether, an alkyl Examples include cationic activators such as amine salts and quaternary ammonium salts. The dispersant may be contained alone or in combination of two or more. The content of the dispersant (solid content or active ingredient) is preferably 10 to 40 parts by weight based on 100 parts by weight of the azo pigment composition from the viewpoint of dispersion stability.

Examples of the dispersion aid include the above-mentioned pigment derivative and dispersion resin. The pigment derivative may be unnecessary when it is contained in the azo pigment composition, but may be further added from the viewpoint of further improving the dispersion stability of particles in the coloring composition. From the viewpoint of dispersion stability, the content of the pigment derivative (solid content or active ingredient) is preferably 2 to 15 parts by weight with respect to 100 parts by weight of the azo pigment composition. When the azo pigment composition contains a pigment derivative, it is based on the total amount. The dispersion resin is particularly preferably used when the coating film forming component contains a photopolymerizable component. Examples of such a dispersion resin include alkali-soluble resins described below. The dispersion resin may be the same resin species as the alkali-soluble resin used as the coating film forming component, or may be a different resin species. The content of the dispersion resin is preferably 10 to 50 parts by weight based on 100 parts by weight of the total of the pigment composition and the pigment derivative.

Examples of the solvent include various organic solvents such as aromatic solvents, ketone solvents, ester solvents, glycol ether solvents, alcohol solvents, and aliphatic solvents. These can be appropriately selected depending on the type of coating film forming component. From the viewpoint of handleability, the solvent can be added so that the solid content concentration including the azo pigment composition and the like is 10 to 30% by weight.

Examples of the coating film forming component include polymers such as thermoplastic urethane resin, (meth)acrylic resin, polyamide resin, polyimide resin, styrene-maleic acid resin, polyester resin, silicone resin and cardo resin. , And a polymerizable component such as a photopolymerizable component. As the polymer, an alkali-soluble resin that is soluble in a solution in the alkaline region is preferable. The content of the polymer in the colored composition is preferably 10 to 40% by weight based on the total solid content of the colored composition. When the above-mentioned dispersion resin is used, it is the total amount. The photopolymerizable component includes a photopolymerizable compound and a photopolymerization initiator. As such a photopolymerizable compound and a photopolymerization initiator, for example, those described in JP 2009-179789 A can be used. The content of the photopolymerizable compound in the colored composition is preferably 5 to 70% by weight, based on the total nonvolatile components in the colored composition, and the content of the photopolymerization initiator in the colored composition is 0.1 to 10 mass% is preferable with respect to the total nonvolatile components of the composition.

Other additives include other pigments, dyes, sensitizers (sensitizing dyes), chain transfer agents, fluorine-based organic compounds, thermal polymerization initiators, thermal polymerization components, fillers, surfactants, adhesion promoters. , Antioxidants, anti-aggregation agents, surface conditioners (leveling agents) and the like. The other pigments and dyes are pigments and dyes used together with the above-mentioned main azo pigment for toning.

The coating film-forming coloring composition can be obtained by adding the above-mentioned components to a known disperser such as a bead mill, a sand mill, a disper, and the like to disperse them. Further, as a method of adding each component, all the components may be mixed and dispersed, or, among the respective components, some components may be mixed and dispersed, and then the remaining components at once, or You may add and disperse|distribute in multiple times. For example, a pigment dispersion containing an azo pigment composition, a dispersant, a solvent, and optionally a dispersion aid is prepared, and a film-forming component and, if necessary, an additive are added and dispersed. You can

Next, the coloring composition for inkjet ink and the outline of the inkjet ink will be described, taking the case of using the above-mentioned azo pigment composition as an example of the coloring agent for inkjet ink for recording.

The coloring composition for inkjet ink contains the above-mentioned azo pigment composition, a dispersant, a dispersion aid, a solvent, and other additives. Among these, a dispersion aid, a solvent, and other additives can be added as necessary according to the components of the azo pigment composition.

As the dispersant, for example, the same dispersant as in the case of the above-mentioned coating composition-forming coloring composition can be used. Further, for example, a resin-type dispersant containing a copolymer containing a cyclohexyl methacrylate unit and an acrylic acid unit described in WO 2012/118078 can be used. The content of the dispersant (solid content or active ingredient) is preferably 10 to 40 parts by weight based on 100 parts by weight of the azo pigment composition from the viewpoint of dispersion stability.

Examples of the dispersion aid include the above-mentioned pigment derivatives. When the pigment derivative is contained in the azo pigment composition, as in the case of the coating film-forming coloring composition described above, it can be added if necessary. From the viewpoint of dispersion stability, the content of the pigment derivative (solid content or active ingredient) is preferably 2 to 14 parts by weight with respect to 100 parts by weight of the azo pigment composition. When the azo pigment composition contains a pigment derivative, it is based on the total amount.

As the solvent, either an organic solvent or an aqueous solvent may be used.

The organic solvent is an organic solvent excluding an aqueous solvent, which is commonly used in inkjet inks, such as alcohols, ketones, esters, glycol ethers, glycol acetates, saturated hydrocarbons, unsaturated hydrocarbons. Organic solvents such as compounds, cyclic saturated hydrocarbons, cyclic unsaturated hydrocarbons and aromatic hydrocarbons can be widely used.

Examples of the aqueous solvent include water and/or a water-soluble organic solvent. As water, for example, deionized water, ultrafiltered water, reverse osmosis water, distilled water, or other pure water or ultrapure water can be used. The water-soluble organic solvent is not particularly limited as long as it is generally used for inkjet inks. Specifically, those having a vapor pressure lower than that of water, for example, polyhydric alcohols such as diethylene glycol, polyhydric alcohol ethers such as triethylene glycol monobutyl ether, ketones, esters, lower alkoxy alcohols, amines , Amides, heterocycles, sulfoxides, sulfones and the like. In addition, those sterilized by UV treatment, hydrogen peroxide solution treatment, etc. may be used for the purpose of preventing the generation of mold and bacteria. Here, the term “water-soluble” means that it is miscible with water or exhibits a solubility in water of 3.3 g/100 mL or more at 20° C.

The content of the solvent is not particularly limited, but is generally 200 to 600 parts by weight with respect to 100 parts by weight of the pigment composition (solid content).

Other additives include other pigments and dyes, surface tension adjusting agents or penetrants (surfactants), wetting and drying inhibitors, preservatives, bactericides, pH adjusting agents, rust preventives, moisturizers and the like. To be These may be used alone or in an appropriate combination of two or more, if necessary.

The pH adjuster is not particularly limited as long as it can be adjusted to a desired pH, and known ones can be used. For example, organic amines such as methylamine and ethylamine; lower alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; inorganic bases such as ammonium hydroxide, sodium hydroxide and potassium hydroxide. Are listed.

Further, the coloring composition for inkjet ink preferably has a viscosity of about 2 to 50 mPa·s as measured by the method described below. This makes it possible to maintain the viscosity of the inkjet ink containing the coloring composition for inkjet ink at a low level, and it becomes possible to eject the inkjet ink from a more stable nozzle and obtain better ejection performance. Become.

In addition, the coloring composition for inkjet ink preferably has a pH of approximately 7 to 10, particularly when an aqueous solvent is used. Thereby, the storage stability of the inkjet ink coloring composition becomes better.

The method for producing the coloring composition for inkjet ink is not particularly limited, and examples thereof include a method in which the above-mentioned azo pigment composition, a dispersant, and other optional components are added and dispersed with a disper/high-speed disper or the like. Furthermore, you may disperse|distribute with a bead mill, a roll mill, etc. as needed. Then, finally, in order to remove particles having a certain size or more that may be contained in the obtained coloring composition for inkjet ink, filter filtration or centrifugation is performed. Further, when performing filter filtration, the pore size (mesh size) of the filter is appropriately adjusted so that the particle size of the particles contained in the inkjet ink coloring composition is adjusted to a predetermined particle size, if necessary. You may choose. Of course, the filter filtration may be performed at the stage of preparing the inkjet ink coloring composition, but may be performed at the stage of preparing the inkjet ink, and it may be performed at the time of preparing the inkjet ink coloring composition and the inkjet ink. It may be done in stages.

Examples of the inkjet ink include those obtained by adding a solvent, a surfactant, and other additives, which are conventionally known as components contained in the inkjet ink, to the above-described coloring composition for inkjet ink, if necessary. To be The content of each component contained in the inkjet ink is not particularly limited, but the content of the pigment composition (solid content) is preferably about 2 to 10% by weight, and the content of the dispersant is about 1 to 10% by weight. %, and the content of the solvent is preferably about 70 to 97% by weight.

The method for producing the inkjet ink is not particularly limited, and for example, it can be obtained by adding a solvent, a surfactant, and other additives as needed to the coloring composition for inkjet ink, mixing and stirring. The method of mixing and stirring is not particularly limited, and a general mixer may be used, or a bead mill may be used to further improve the dispersibility of the pigment. If necessary, in order to remove particles of a certain size or larger that may be contained in the ink, filter filtration or the like may be performed.

Since the above-mentioned inkjet ink contains a predetermined azo pigment composition, when used as a recording ink, it has an excellent print density (coloring property). The print density (color developability) can be determined using, for example, a measured value of optical density (OD) described later as an index. When the optical density (OD) is 1.1 to 1.3, it can be judged that the print density is excellent.

Hereinafter, embodiments of the present invention will be described in more detail based on examples.

(Production Example 1) Production of pigment derivative (I) C.I. I. Pigment Yellow 138 (manufactured by BASF, Pliotol Gelb K0961HD) (20 parts by weight) and 98% sulfuric acid (300 parts by weight) were placed in a 500 ml separable flask and reacted at 120° C. for 5 hours to obtain a sulfonated phthalimidoquinophthalone compound. .. The reaction mixture was poured into 3000 parts of water with stirring to precipitate a sulfonated phthalimidoquinophthalone compound, stirred for 30 minutes, and then filtered and washed with water three times. The obtained wet cake was washed with 300 parts by weight of 1% diluted sulfuric acid, filtered, and washed with water. The pigment derivative (I) represented by the following formula (5) was obtained in 54 parts by weight by drying in a hot air drier. The obtained pigment derivative (I) was subjected to mass spectrometry using a liquid chromatography mass spectrometer “LC/MS” (Electro Spray Ionization) manufactured by Hewlett-Packard Company, and as a result, m/z 733 [MH] ⁻ was detected. did. The elemental analysis and the mass spectrometric analysis of the pigment derivative (I) were p=0.8.

(Example 1)
50 g (0.21 mol) of 3-amino-4-methoxybenzanilide and 1.2 g (0.0069 mol) of sulfanilic acid as a heterogeneous base were dispersed in 1000 g of water, ice was added, and the temperature condition was 0 to 5°C. Then, 55 g (0.53 mol) of 35% hydrochloric acid aqueous solution was added, and the mixture was stirred for 30 minutes. Then, 50 g (0.22 mol) of 30% sodium nitrite aqueous solution was added and stirred for 60 minutes, and then 1.2 g (0.012 mol) of sulfamic acid for eliminating excess nitrous acid was added. Further, 40 g (0.29 mol) of sodium acetate and 58 g (0.87 mol) of 90% acetic acid were added to obtain a diazonium salt solution. Separately, 64 g (0.1954 mol) of N-(5-chloro-2-methoxyphenyl)-3-hydroxy-2-naphthalenecarboxamide and 4.4 g (0.0235 mol) of BON acid as a heterogeneous coupler were added. A coupler solution was prepared by dissolving 1000 g of water and 25 g (0.63 mol) of caustic soda at a temperature of 80° C. or lower. This solution was added to the above diazonium salt solution under a temperature condition of 10°C or lower, a coupling reaction was carried out, and heat treatment was carried out at 90°C. The reaction mixture was filtered, washed with water, and then dried at 100°C. Then, the dried product was crushed to obtain a crushed product. The content of Pigment Red 269, which is a reaction product of 3-amino-4-methoxybenzanilide diazotized product and N-(5-chloro-2-methoxyphenyl)-3-hydroxy-2-naphthalenecarboxamide, was 89. It was 0.1% by weight. The weight ratio ((1)/(3)) of the components derived from the main base (1) and the heterogeneous base (3) was 97.1/2.9, and the weight ratio was derived from the main coupler (2) and the heterogeneous coupler (4). The weight ratio of the components ((2)/(4)) was 91.7/8.3.

The obtained pulverized product was subjected to a refining treatment as described below to obtain a finely divided azo pigment composition. That is, 300 g of pulverized product, 45 g of surface treatment agent (Lipoxy (registered trademark) SPC2000, Showa Denko KK, vinyl ester resin), 3000 g of Glauber's salt as a grinding agent, ethylene glycol (made by Nippon Shokubai Co., Ltd.) as a binder. 800 g was charged into a double-arm type kneader (manufactured by Moriyama, 5 L kneader Σ type, hereinafter referred to as kneader), and the temperature was controlled so that the temperature of the kneaded product in the kneader was 40° C. and kneading was performed for 9 hours. When the kneading is completed, the kneaded product is taken out, transferred to a temperature-controllable tank in which 16 L of deionized water is stored in advance, stirred with a stirrer at a rotation speed of 180 rpm for 30 minutes, and the pH is adjusted to 2.3 with 35% hydrochloric acid. After adjusting to ~2.5, the mixture was further stirred for 1 hour to disperse the kneaded product. The dispersion was transferred to a Nutsche and filtered, and the residue was washed with deionized water until the electric conductivity of the washing drainage was 3 μS/cm or less. The water-containing residue after washing with water was taken out, collected in a drying shelf (material SUS304), transferred to a dryer and dried at 95° C. for 20 hours. The dried product was pulverized with a pulverizer (manufactured by Kyoritsu Riko Co., Ltd., small pulverizer, sample mill SK-M2) to obtain a fine powdered azo pigment composition. The average primary particle diameter of the particles in the atomized azo pigment composition was 50 nm.

(Example 2)
Micronization was performed in the same manner as in Example 1 except that the amount of sulfanilic acid added was 0.7 g (0.0040 mol) and the amount of BON acid added was 2.5 g (0.013 mol). A powdery azo pigment composition was obtained. Pigment Red 269 was 93.6% by weight. The weight ratio ((1)/(3)) of the components derived from the main base (1) and the heterogeneous base (3) was 98.3/1.7, and was derived from the main coupler (2) and the heterogeneous coupler (4). The weight ratio of the components ((2)/(4)) was 95.2/4.8. The average primary particle diameter of the particles in the atomized azo pigment composition was 55 nm.

(Example 3)
A finely divided powdery azo pigment composition was obtained in the same manner as in Example 1 except that 5.4 g (0.0235 mol) of sodium shefferate was used instead of 4.4 g (0.0235 mol) of BON acid. I got a thing. Pigment Red 269 was 88.1% by weight. The weight ratio ((1)/(3)) of the components derived from the main base (1) and the heterogeneous base (3) was 97.1/2.9, and the weight ratio was derived from the main coupler (2) and the heterogeneous coupler (4). The weight ratio of the components ((2)/(4)) was 90.6/9.4. The average primary particle diameter of the particles in the atomized azo pigment composition was 65 nm.

(Example 4)
A finely divided powdery azo pigment composition was prepared in the same manner as in Example 1 except that F acid (5.3 g, 0.0235 mol) was used instead of BON acid (4.4 g, 0.0235 mol). Got Pigment Red 269 was 88.5% by weight. The weight ratio ((1)/(3)) of the components derived from the main base (1) and the heterogeneous base (3) was 97.1/2.9, and the weight ratio was derived from the main coupler (2) and the heterogeneous coupler (4). The weight ratio of the components ((2)/(4)) was 91.1/8.9. The average primary particle diameter of the particles in the atomized azo pigment composition was 60 nm.

(Comparative Example 1)
A dried product was obtained in the same manner as in Example 1 except that sulfanilic acid and BON acid were not added, and then finely treated to obtain a powdery azo pigment composition. The average primary particle diameter of the particles in the obtained azo pigment composition was 90 nm.

(Comparative example 2)
A dried product was obtained in the same manner as in Example 1 except that BON acid was not added, and then finely divided to obtain a powdery azo pigment composition. The average primary particle diameter of the particles in the obtained azo pigment composition was 100 nm.

(Comparative example 3)
A dried product was obtained in the same manner as in Example 1 except that sulfanilic acid was not added, and then finely treated to obtain a powdery azo pigment composition. The average primary particle diameter of the particles in the obtained azo pigment composition was 120 nm.

(Comparative Example 4)
After obtaining a dried product in the same manner as in Example 1 except that 0.95 g (0.0069 mol) of p-aminobenzoic acid was used instead of 1.2 g (0.0069 mol) of sulfanilic acid, Chemical treatment was performed to obtain a powdery azo pigment composition. Pigment Red 269 was 87.8% by weight. The weight ratio ((1)/(3)) of the components derived from the main base (1) and the heterogeneous base (3) was 97.3/2.7, and was derived from the main coupler (2) and the heterogeneous coupler (4). The weight ratio of the components ((2)/(4)) was 91.7/8.3. The average primary particle diameter of the particles in the obtained azo pigment composition was 80 nm.

(Comparative example 5)
After obtaining a dried product in the same manner as in Example 1 except that 3.4 g (0.0235 mol) of β-naphthol was used instead of 4.4 g (0.0235 mol) of BON acid, micronization treatment was performed. Then, a powdery azo pigment composition was obtained. Pigment Red 269 was 89.8% by weight. The weight ratio ((1)/(3)) of the components derived from the main base (1) and the heterogeneous base (3) was 97.1/2.9, and the weight ratio was derived from the main coupler (2) and the heterogeneous coupler (4). The weight ratio of the components ((2)/(4)) was 92.4/7.6. The average primary particle diameter of the particles in the obtained azo pigment composition was 110 nm.

(Test Example 1)
<Preparation of Pigment Dispersions A1 to 9>
Azo pigment compositions obtained in Examples 1 to 4 and Comparative Examples 1, 2, and 5: 22.5% by weight, Pigment derivative (I) obtained in Production Example 1: 2.5% by weight (azo pigment composition 11.1 wt% of the product (hereinafter, the azo pigment composition and the pigment derivative (I) may be collectively referred to as a colorant component), a polymer dispersant (manufactured by Big Chemie Japan, Disperbyk). LPN-21715): solid content is 28% by weight with respect to the colorant component, polymer dispersant (manufactured by Big Chemie Japan, Disperbyk 111): solid content is 2% by weight with respect to the colorant component, dispersion resin ( Soret Chemical Co., Ltd., Follet (registered trademark) ZAH110, solid content 35.0%, soluble in alkali): Solid content 20% by weight with respect to colorant component, propylene glycol monomethyl ether (PM) as solvent: 10% by weight Propylene glycol monomethyl ether acetate (PMA) as a solvent: The rest was put into a stirrer (uniaxial mixer) having an internal capacity of 550 ml and stirred for 10 minutes. Next, 480 g of zirconia beads having an average particle diameter of 0.8 mm (Toray ceram crushed ball, manufactured by Toray Industries, Inc.) was added, and the mixture was stirred for 30 minutes in a constant temperature bath at 40° C. for dispersion treatment. Then, PMA was added so that the azo pigment composition was 20% by weight, the mixture was stirred for 10 minutes, and the zirconia beads were removed by filtration. Next, zirconia beads having an average particle diameter of 0.1 mm (Toray ceram crushed ball, manufactured by Toray Industries, Inc.) were added by 4 times the total amount charged by weight, and the mixture was stirred in a constant temperature bath at 40° C. for 50 minutes for dispersion treatment. It was Then, PMA was added so that the azo pigment composition was 15% by weight, the mixture was stirred for 10 minutes, and the zirconia beads were removed by filtration using a filter (PALL HDCII Membrane Filter, manufactured by PALL) to disperse the pigment. The bodies A1 to 6 and 9 were obtained.

When the same dispersion treatment was carried out using the azo pigment compositions obtained in Comparative Examples 3 and 4, the desired pigment dispersions A7 and 8 could not be obtained due to gelation. Therefore, the following evaluation was not performed.

<Evaluation>
<<Formation of coating film>>
The pigment dispersions A1 to 6 and 9 are coated so that the azo pigment composition is 12% by weight, and the total amount of the dispersion resin and the polymeric dispersant is 100% by weight based on the azo pigment composition. Forming components (Foret (registered trademark) ZAH110, acrylic polymer, solid content 35.0%, alkali-soluble) manufactured by Soken Kagaku Co., Ltd. and PMA were added to prepare colored compositions A1 to 6 and 9. The obtained coloring compositions A1 to 6 and 9 were applied to glass plates having a thickness of 1 mm and 100 mm square by using a spin coater (Minasa Co., Ltd., spin coater MS-150A). At this time, for each of the coloring compositions A1 to 6 and 9, three coated plates were prepared so that three coating films having different chromaticities x were formed. That is, the thickness is changed by changing the rotational speed of the spin coater so that the chromaticity x of one of the three sheets is always smaller than 0.6850, and the chromaticity x of the other sheet is always 0. The value is set to be larger than 0.6850. The obtained coated plate was pre-dried at 90° C. for 2.5 minutes (Prebake), and further dried at 230° C. for 30 minutes (Postbake).

<<Measurement of chromaticity y, brightness Y, contrast>>
For each coating film after Prebake and Postbake, a tristimulus value by the xyY colorimetric method was determined using a chromaticity meter (U3310, manufactured by Hitachi, Ltd.). The contrast ratio (CR ratio) was determined using a color luminance meter (Topcon Techno House, BM-5AS). An approximate straight line (calibration curve) is obtained from the measured values of the three coated plates prepared as described above for each coating film, and the chromaticity y(Ry) and the luminance when the chromaticity x(Rx) is 0.6850. The value of Y(RY) was taken as the result for each coating. Based on the coating film A1 obtained by using the coloring composition A1, a difference ΔRY (RY(A2-6,9)-RY(A1)) in RY between the coating films A2 to 6 and 9 and a CR ratio (A2). .About.6, 9/A1) was determined. The results are shown in Table 1.

(Test Example 2)
<Preparation of Pigment Dispersion B>
In order to evaluate the brightness and the contrast by combining the hues (Rx, Ry), a pigment dispersion B containing a yellow pigment for toning was prepared as follows. First, as a yellow pigment for toning, C.I. I. Pigment Yellow 139 (manufactured by BASF, product name Irgaphor Yellow S2150CF) was used in the same manner as Pigment Dispersion A, except that the yellow pigment was used instead of the azo pigment composition obtained in Example 1. A yellow pigment dispersion (Y) for color was obtained. Next, Pigment Dispersions A1 to 6 and 9 (R) and Toning Yellow Pigment Dispersion (Y) were mixed at a mixing ratio (R/Y, weight basis) of Table 2 to obtain Pigment Dispersion B ( C. I. Pigment Yellow 139 and a total of 15% by weight of colorant components and a solid content of 22.50%) were prepared.

<Evaluation>
Using the obtained pigment dispersions B1 to 6 and 9, coloring compositions B1 to 6 and 9 and coating films B1 to 6 and 9 were prepared in the same manner as in Test Example 1, and the chromaticity y ( Ry), luminance Y (RY), and contrast (CR) were measured and evaluated. The results are shown in Table 2.

From Tables 1 and 2, when an azo pigment, which is a reaction product of a specific base and a coupler, is produced, by adding a specific base and a coupler different from the base and the coupler, a conventional production method can be obtained. It is understood that the azo pigment and the azo pigment composition can provide an azo pigment composition capable of forming a coating film excellent in contrast and brightness.

(Production Example 2) Production of polymeric dispersant After purging the inside of a 1000 ml separable flask equipped with a stirrer, a cooler, a thermometer, a dropping funnel with nitrogen, 200 parts by weight of butyl acetate was placed in the separable flask, The temperature was raised to 100° C. with stirring. Then, 200 parts by weight of butyl acetate, 252 parts by weight of cyclohexyl methacrylate (CHMA), 4 parts by weight of styrene (St), 56 parts by weight of butyl acrylate (BA), 88 parts by weight of acrylic acid (AA) and azobisisobutyrate were added to the dropping funnel. 14 parts by weight of ronitrile was added, and the mixture was added dropwise to the separable flask at 100°C over 4 hours. After completion of dropping, the reaction was completed by holding for 1 hour. The end point of the reaction was judged by measuring the unreacted monomer in the reaction solution by gas chromatography. Then, butyl acetate was removed by distillation under reduced pressure to obtain a copolymer. The obtained copolymer contained monomers in a weight ratio of CHMA/BA/AA/St=63/14/22/1, an acid value of 160 mg-KOH/g and a weight average molecular weight of 5,300. This copolymer was used as a dispersant.

(Evaluation)
<Measurement of average particle size>
The average particle size of the particles contained in the inkjet ink obtained in Example 5 was measured using a laser zeta potentiometer (ELS-8000, manufactured by Otsuka Electronics Co., Ltd.).

<Measurement of viscosity>
The viscosity of the inkjet ink obtained in Example 5 was measured at 25° C. using a TV-22 type viscometer manufactured by Toki Sangyo Co., Ltd.

<pH measurement>
The pH of the inkjet ink obtained in Example 5 was measured at 25° C. using a pH meter F-54 manufactured by HORIBA, Ltd.

<Evaluation of print density>
Using the inkjet ink obtained in Example 5, solid printing was performed on plain paper (made by Seiko Epson Co., Ltd., double-sided fine plain paper) with an inkjet printer, and the print density (optical density: OD) was measured to determine the color developability. It was used as an index. As the optical density (OD), GRETAG (registered trademark) RD-19 manufactured by Gretag Macbeth was used, and OD was measured at 5 points, and an average value of them was adopted.

(Example 5)
15 parts by weight of the finely divided azo pigment composition prepared in Example 1, 4.50 parts by weight (solid content) of the dispersant obtained in Production Example 2, and 0.45 of a 30% aqueous sodium hydroxide solution as a pH adjuster. Parts by weight, 1.35 parts by weight of triethanolamine as a pH adjusting agent, 0.2 parts by weight of Biokiller LS (manufactured by KAI Kasei Co., Ltd.) as an antiseptic fungicide, and BYK024 (manufactured by BYK Japan Japan) as an antifoaming agent. ) 0.05 parts by weight was mixed, ion-exchanged water was added so that the pigment content was 20% by weight, and the mixture was stirred for 1 hour with a high-speed disper to obtain a pigment-dispersed slurry. The pigment-dispersed slurry was placed in a cylindrical container filled with zirconia beads having a diameter of 0.65 mm, and dispersed by an agitator at a rotation speed of 2000 rpm for 1.5 hours to obtain a pigment dispersion. The obtained pigment dispersion was filtered with a filter having a pore size of 5 μm (manufactured by F-Tech Co., Ltd.) to obtain a coloring composition for inkjet ink. Ion-exchanged water was added to the obtained coloring composition for inkjet ink to a pigment concentration of 15% by weight to prepare an aqueous inkjet ink. The above-mentioned evaluation was performed using the obtained inkjet ink. As a result, the average particle diameter was 159 nm, the viscosity was 8.2 mPa·s, the pH was 9.9, and the OD was 1.17, which was a good result as an inkjet ink.

Claims (6)

In the production of an azo pigment, which is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2), a heterogeneous base represented by the formula (3) and a different base represented by the formula (4) are used. A method for producing an azo pigment composition, wherein the heterogeneous coupler shown is added.

(In the formula (1), R ¹ represents R ³ —NH—C(═O)—, R ² represents a halogen atom or R ⁴ O—, and R ³ represents a hydrogen atom or a phenyl group (—C ₆ H). ₅ ) is shown.R< ⁴ > shows a C1-C4 alkyl group.)

(In the formula (2), R ⁵ represents a hydrogen atom or —CONH—R ^6, and R ⁶ represents the following formula (2-1).)

(In the formula (2-1), R ⁷ represents R ⁹ —NH—C(═O)—, R ⁸ represents a halogen atom or R ¹⁰ O—, and R ⁹ represents a hydrogen atom or a phenyl group (—C). ₆ H ₅ ). R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.

(In the formula ^{(4), R 11} represents an -SO ₃ H or -COOH.) For 100 parts by weight of the base represented by the formula (1), 0.5 to 4 parts by weight of the base represented by the formula (3), and for 100 parts by weight of the coupler represented by the formula (2), the formula (4 ) The method for producing an azo pigment composition according to claim 1, wherein 2 to 10 parts by weight of the coupler shown in FIG. The method for producing an azo pigment composition according to claim 1, wherein the azo pigment composition is subjected to a refining treatment so that the average primary particle diameter of the azo pigment becomes 25 to 70 nm. The method for producing an azo pigment composition according to claim 3, wherein the micronization treatment is performed in the presence of a pigment derivative. An azo pigment composition comprising an azo pigment which is a reaction product of a base represented by the following formula (1) and a coupler represented by the following formula (2):
The reaction products of the bases represented by the formulas (1) and (3) and the couplers represented by the formulas (2) and (4) are contained, and the content of the reaction products of the formulas (1) and (2) (solid content Azo pigment composition having a content of 80 to 95% by weight.

(In the formula (1), R ¹ represents R ³ —NH—C(═O)—, R ² represents a halogen atom or R ⁴ O—, and R ³ represents a hydrogen atom or a phenyl group (—C ₆ H). ₅ ), and R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms.)

(In formula (2), R ⁵ represents a hydrogen atom or -CONH-R ^6. R ⁶ represents the following formula (2-1).)

(In formula (2-1), R ⁷ represents R ⁹ —NH—C(═O)—, R ⁸ represents a halogen atom or R ¹⁰ O—, and R ⁹ represents a hydrogen atom or a phenyl group (—C). ₆ H ₅ ). R ¹⁰ represents an alkyl group having 1 to 4 carbon atoms, and * represents a bond.)

(In the formula ^{(4), R 11} represents an -SO ₃ H or -COOH.) The weight ratio ((1)/(3)) of the component derived from the formula (1) and the component derived from the formula (3) is 90.6/9.4 to 98.9/1.1, and the formula ( The weight ratio ((2)/(4)) of the component derived from 2) and the component derived from Formula (4) is 82.4/17.6-96.5/3.5. Azo pigment composition.